Re: speed decrease since firefly,giant,hammer the 2nd try

[Mark Nelson <mnelson@xxxxxxxxxx>]

On 02/16/2015 08:50 AM, Stefan Priebe - Profihost AG wrote:
> Hi Mark,
>    Hi Alexandre,
>
> Am 16.02.2015 um 10:11 schrieb Alexandre DERUMIER:
> > Hi Stefan,
> >
> > I could be interesting to see if you have the same speed decrease with fio-librbd on the host,
> > without the qemu layer.
> >
> > the perf reports don't seem to be too much different.
> > do you have the same cpu usage ? (check qemu process usage)
>
> the idea to use fio-librbd was very good.
>
> I cannot reproduce the behaviour using fio-rbd. I can just reproduce it
> with qemu.
>
> Very strange. So please ignore me for the moment. I'll try to dig deeper
> into it.

Interesting development!  FWIW, I've been doing some testing with 
librados on dumpling, firefly, and hammer.  Not RBD numbers, but adds a 
bit of info to the greater puzzle.

Hoping I should have something written up this week.

> Greets,
> Stefan
>
> > ----- Mail original -----
> > De: "Stefan Priebe" <s.priebe@xxxxxxxxxxxx>
> > À: "Mark Nelson" <mnelson@xxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
> > Envoyé: Dimanche 15 Février 2015 19:40:45
> > Objet: Re: speed decrease since firefly,giant,hammer the 2nd try
> >
> > Hi Mark,
> >
> > what's next?
> >
> > I've this test cluster only for 2 more days.
> >
> > Here some perf Details:
> >
> > dumpling:
> > 12,65% libc-2.13.so [.] 0x79000
> > 2,86% libc-2.13.so [.] malloc
> > 2,80% kvm [.] 0xb59c5
> > 2,59% libc-2.13.so [.] free
> > 2,35% [kernel] [k] __schedule
> > 2,16% [kernel] [k] _raw_spin_lock
> > 1,92% [kernel] [k] __switch_to
> > 1,58% [kernel] [k] lapic_next_deadline
> > 1,09% [kernel] [k] update_sd_lb_stats
> > 1,08% [kernel] [k] _raw_spin_lock_irqsave
> > 0,91% librados.so.2.0.0 [.] ceph_crc32c_le_intel
> > 0,91% libpthread-2.13.so [.] pthread_mutex_trylock
> > 0,87% [kernel] [k] resched_task
> > 0,72% [kernel] [k] cpu_startup_entry
> > 0,71% librados.so.2.0.0 [.] crush_hash32_3
> > 0,66% [kernel] [k] leave_mm
> > 0,65% librados.so.2.0.0 [.] Mutex::Lock(bool)
> > 0,64% [kernel] [k] idle_cpu
> > 0,62% libpthread-2.13.so [.] __pthread_mutex_unlock_usercnt
> > 0,59% [kernel] [k] try_to_wake_up
> > 0,56% [kernel] [k] wake_futex
> > 0,50% librados.so.2.0.0 [.] ceph::buffer::ptr::release()
> >
> > firefly:
> > 12,56% libc-2.13.so [.] 0x7905d
> > 2,82% libc-2.13.so [.] malloc
> > 2,64% libc-2.13.so [.] free
> > 2,61% kvm [.] 0x34322f
> > 2,33% [kernel] [k] __schedule
> > 2,14% [kernel] [k] _raw_spin_lock
> > 1,83% [kernel] [k] __switch_to
> > 1,62% [kernel] [k] lapic_next_deadline
> > 1,17% [kernel] [k] _raw_spin_lock_irqsave
> > 1,09% [kernel] [k] update_sd_lb_stats
> > 1,08% libpthread-2.13.so [.] pthread_mutex_trylock
> > 0,85% libpthread-2.13.so [.] __pthread_mutex_unlock_usercnt
> > 0,77% [kernel] [k] resched_task
> > 0,74% librbd.so.1.0.0 [.] 0x71b73
> > 0,72% librados.so.2.0.0 [.] Mutex::Lock(bool)
> > 0,68% librados.so.2.0.0 [.] crush_hash32_3
> > 0,67% [kernel] [k] idle_cpu
> > 0,65% [kernel] [k] leave_mm
> > 0,65% [kernel] [k] cpu_startup_entry
> > 0,59% [kernel] [k] try_to_wake_up
> > 0,51% librados.so.2.0.0 [.] ceph::buffer::ptr::release()
> > 0,51% [kernel] [k] wake_futex
> >
> > Stefan
> >
> > Am 11.02.2015 um 06:42 schrieb Stefan Priebe:
> > > Am 11.02.2015 um 05:45 schrieb Mark Nelson:
> > > > On 02/10/2015 04:18 PM, Stefan Priebe wrote:
> > > > > Am 10.02.2015 um 22:38 schrieb Mark Nelson:
> > > > > > On 02/10/2015 03:11 PM, Stefan Priebe wrote:
> > > > > > > mhm i installed librbd1-dbg and librados2-dbg - but the output still
> > > > > > > looks useless to me. Should i upload it somewhere?
> > > > > >
> > > > > > Meh, if it's all just symbols it's probably not that helpful.
> > > > > >
> > > > > > I've summarized your results here:
> > > > > >
> > > > > > 1 concurrent 4k write (libaio, direct=1, iodepth=1)
> > > > > >
> > > > > > IOPS Latency
> > > > > > wb on wb off wb on wb off
> > > > > > dumpling 10870 536 ~100us ~2ms
> > > > > > firefly 10350 525 ~100us ~2ms
> > > > > >
> > > > > > So in single op tests dumpling and firefly are far closer. Now let's
> > > > > > see each of these cases with iodepth=32 (still 1 thread for now).
> > > > >
> > > > >
> > > > > dumpling:
> > > > >
> > > > > file1: (g=0): rw=randwrite, bs=4K-4K/4K-4K, ioengine=libaio, iodepth=32
> > > > > 2.0.8
> > > > > Starting 1 thread
> > > > > Jobs: 1 (f=1): [w] [100.0% done] [0K/72812K /s] [0 /18.3K iops] [eta
> > > > > 00m:00s]
> > > > > file1: (groupid=0, jobs=1): err= 0: pid=3011
> > > > > write: io=2060.6MB, bw=70329KB/s, iops=17582 , runt= 30001msec
> > > > > slat (usec): min=1 , max=3517 , avg= 3.42, stdev= 7.30
> > > > > clat (usec): min=93 , max=7475 , avg=1815.72, stdev=233.43
> > > > > lat (usec): min=219 , max=7477 , avg=1819.27, stdev=233.52
> > > > > clat percentiles (usec):
> > > > > | 1.00th=[ 1480], 5.00th=[ 1576], 10.00th=[ 1608], 20.00th=[
> > > > > 1672],
> > > > > | 30.00th=[ 1704], 40.00th=[ 1752], 50.00th=[ 1800], 60.00th=[
> > > > > 1832],
> > > > > | 70.00th=[ 1896], 80.00th=[ 1960], 90.00th=[ 2064], 95.00th=[
> > > > > 2128],
> > > > > | 99.00th=[ 2352], 99.50th=[ 2448], 99.90th=[ 4704], 99.95th=[
> > > > > 5344],
> > > > > | 99.99th=[ 7072]
> > > > > bw (KB/s) : min=59696, max=77840, per=100.00%, avg=70351.27,
> > > > > stdev=4783.25
> > > > > lat (usec) : 100=0.01%, 250=0.01%, 500=0.01%, 750=0.01%, 1000=0.53%
> > > > > lat (msec) : 2=85.02%, 4=14.31%, 10=0.13%
> > > > > cpu : usr=1.96%, sys=6.71%, ctx=22791, majf=0, minf=133
> > > > > IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=100.0%,
> > > > > > =64=0.0%
> > > > > submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%,
> > > > > > =64=0.0%
> > > > > complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.1%, 64=0.0%,
> > > > > > =64=0.0%
> > > > > issued : total=r=0/w=527487/d=0, short=r=0/w=0/d=0
> > > > >
> > > > > Run status group 0 (all jobs):
> > > > > WRITE: io=2060.6MB, aggrb=70329KB/s, minb=70329KB/s, maxb=70329KB/s,
> > > > > mint=30001msec, maxt=30001msec
> > > > >
> > > > > Disk stats (read/write):
> > > > > sdb: ios=166/526079, merge=0/0, ticks=24/890120, in_queue=890064,
> > > > > util=98.73%
> > > > >
> > > > > firefly:
> > > > >
> > > > > file1: (g=0): rw=randwrite, bs=4K-4K/4K-4K, ioengine=libaio, iodepth=32
> > > > > 2.0.8
> > > > > Starting 1 thread
> > > > > Jobs: 1 (f=1): [w] [100.0% done] [0K/69096K /s] [0 /17.3K iops] [eta
> > > > > 00m:00s]
> > > > > file1: (groupid=0, jobs=1): err= 0: pid=2982
> > > > > write: io=1784.9MB, bw=60918KB/s, iops=15229 , runt= 30002msec
> > > > > slat (usec): min=1 , max=1389 , avg= 3.43, stdev= 5.32
> > > > > clat (usec): min=117 , max=8235 , avg=2096.88, stdev=396.30
> > > > > lat (usec): min=540 , max=8258 , avg=2100.43, stdev=396.61
> > > > > clat percentiles (usec):
> > > > > | 1.00th=[ 1608], 5.00th=[ 1720], 10.00th=[ 1768], 20.00th=[
> > > > > 1832],
> > > > > | 30.00th=[ 1896], 40.00th=[ 1944], 50.00th=[ 2008], 60.00th=[
> > > > > 2064],
> > > > > | 70.00th=[ 2160], 80.00th=[ 2256], 90.00th=[ 2512], 95.00th=[
> > > > > 2896],
> > > > > | 99.00th=[ 3600], 99.50th=[ 3792], 99.90th=[ 5088], 99.95th=[
> > > > > 6304],
> > > > > | 99.99th=[ 6752]
> > > > > bw (KB/s) : min=36717, max=73712, per=99.94%, avg=60879.92,
> > > > > stdev=8302.27
> > > > > lat (usec) : 250=0.01%, 750=0.01%
> > > > > lat (msec) : 2=48.56%, 4=51.18%, 10=0.26%
> > > > > cpu : usr=2.03%, sys=5.48%, ctx=20440, majf=0, minf=133
> > > > > IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=100.0%,
> > > > > > =64=0.0%
> > > > > submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%,
> > > > > > =64=0.0%
> > > > > complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.1%, 64=0.0%,
> > > > > > =64=0.0%
> > > > > issued : total=r=0/w=456918/d=0, short=r=0/w=0/d=0
> > > > >
> > > > > Run status group 0 (all jobs):
> > > > > WRITE: io=1784.9MB, aggrb=60918KB/s, minb=60918KB/s, maxb=60918KB/s,
> > > > > mint=30002msec, maxt=30002msec
> > > > >
> > > > > Disk stats (read/write):
> > > > > sdb: ios=166/455574, merge=0/0, ticks=12/897748, in_queue=897696,
> > > > > util=98.96%
> > > >
> > > > Ok, so it looks like as you increase concurrency the effect increases
> > > > (ie contention?). Does the same thing happen without cache enabled?
> > >
> > > here again without rbd cache:
> > >
> > > dumpling:
> > > file1: (g=0): rw=randwrite, bs=4K-4K/4K-4K, ioengine=libaio, iodepth=32
> > > 2.0.8
> > > Starting 1 thread
> > > Jobs: 1 (f=1): [w] [100.0% done] [0K/83488K /s] [0 /20.9K iops] [eta
> > > 00m:00s]
> > > file1: (groupid=0, jobs=1): err= 0: pid=3000
> > > write: io=2449.2MB, bw=83583KB/s, iops=20895 , runt= 30005msec
> > > slat (usec): min=1 , max=975 , avg= 4.50, stdev= 5.25
> > > clat (usec): min=364 , max=80566 , avg=1525.87, stdev=1194.57
> > > lat (usec): min=519 , max=80568 , avg=1530.51, stdev=1194.44
> > > clat percentiles (usec):
> > > | 1.00th=[ 660], 5.00th=[ 780], 10.00th=[ 876], 20.00th=[ 1032],
> > > | 30.00th=[ 1144], 40.00th=[ 1240], 50.00th=[ 1304], 60.00th=[ 1384],
> > > | 70.00th=[ 1480], 80.00th=[ 1640], 90.00th=[ 2096], 95.00th=[ 2960],
> > > | 99.00th=[ 6816], 99.50th=[ 7840], 99.90th=[11712], 99.95th=[13888],
> > > | 99.99th=[18816]
> > > bw (KB/s) : min=47184, max=95432, per=100.00%, avg=83639.19,
> > > stdev=7973.92
> > > lat (usec) : 500=0.01%, 750=3.82%, 1000=14.40%
> > > lat (msec) : 2=70.57%, 4=7.91%, 10=3.11%, 20=0.17%, 50=0.01%
> > > lat (msec) : 100=0.01%
> > > cpu : usr=3.12%, sys=11.49%, ctx=74951, majf=0, minf=133
> > > IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=100.0%,
> > > > =64=0.0%
> > > submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%,
> > > > =64=0.0%
> > > complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.1%, 64=0.0%,
> > > > =64=0.0%
> > > issued : total=r=0/w=626979/d=0, short=r=0/w=0/d=0
> > >
> > > Run status group 0 (all jobs):
> > > WRITE: io=2449.2MB, aggrb=83583KB/s, minb=83583KB/s, maxb=83583KB/s,
> > > mint=30005msec, maxt=30005msec
> > >
> > > Disk stats (read/write):
> > > sdb: ios=168/625292, merge=0/0, ticks=144/916096, in_queue=916128,
> > > util=99.93%
> > >
> > >
> > > firefly:
> > >
> > > fio --filename=/dev/sdb --direct=1 --rw=randwrite --bs=4k --numjobs=1
> > > --thread --iodepth=32 --ioengine=libaio --runtime=30 --group_reporting
> > > --name=file1
> > > file1: (g=0): rw=randwrite, bs=4K-4K/4K-4K, ioengine=libaio, iodepth=32
> > > 2.0.8
> > > Starting 1 thread
> > > Jobs: 1 (f=1): [w] [100.0% done] [0K/90044K /s] [0 /22.6K iops] [eta
> > > 00m:00s]
> > > file1: (groupid=0, jobs=1): err= 0: pid=2970
> > > write: io=2372.9MB, bw=80976KB/s, iops=20244 , runt= 30006msec
> > > slat (usec): min=1 , max=4047 , avg= 4.36, stdev= 7.17
> > > clat (usec): min=197 , max=76656 , avg=1575.29, stdev=1165.74
> > > lat (usec): min=523 , max=76660 , avg=1579.79, stdev=1165.59
> > > clat percentiles (usec):
> > > | 1.00th=[ 676], 5.00th=[ 804], 10.00th=[ 916], 20.00th=[ 1096],
> > > | 30.00th=[ 1224], 40.00th=[ 1304], 50.00th=[ 1384], 60.00th=[ 1448],
> > > | 70.00th=[ 1544], 80.00th=[ 1704], 90.00th=[ 2128], 95.00th=[ 2736],
> > > | 99.00th=[ 6752], 99.50th=[ 7904], 99.90th=[12096], 99.95th=[14656],
> > > | 99.99th=[18560]
> > > bw (KB/s) : min=47800, max=91952, per=99.91%, avg=80900.88,
> > > stdev=7234.98
> > > lat (usec) : 250=0.01%, 500=0.01%, 750=2.95%, 1000=11.38%
> > > lat (msec) : 2=73.81%, 4=8.81%, 10=2.85%, 20=0.19%, 50=0.01%
> > > lat (msec) : 100=0.01%
> > > cpu : usr=2.99%, sys=10.60%, ctx=66549, majf=0, minf=133
> > > IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=100.0%,
> > > > =64=0.0%
> > > submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%,
> > > > =64=0.0%
> > > complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.1%, 64=0.0%,
> > > > =64=0.0%
> > > issued : total=r=0/w=607445/d=0, short=r=0/w=0/d=0
> > >
> > > Run status group 0 (all jobs):
> > > WRITE: io=2372.9MB, aggrb=80976KB/s, minb=80976KB/s, maxb=80976KB/s,
> > > mint=30006msec, maxt=30006msec
> > >
> > > Disk stats (read/write):
> > > sdb: ios=170/605440, merge=0/0, ticks=156/916492, in_queue=916560,
> > > util=99.93%
> > >
> > > Stefan
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